Apparatus for making pistons



Dec. 17, 1935. A A HANDLER 2,024,286

APPARATUS FOR MAKING'PISTONS Filed March 18, 1931 2 Sheets-Sheet l 4.4 ez-o ,4. HAN -E wag/X 254.

Dec. 17, 1935.

A. A. HANDLER PARATUS FOR nxme ifxsrons' Filed March 18, p31

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Patented Dec. 17, 1935 UNITED STATES I 2,024,286 APPARATUS FOR MAKING PISTONS Adolf Handler, Cleveland, Ohio, asslgnor to Aluminum Company of America, Pittsburgh, Pa., a. corporation of Pennsylvania Application March 18, 1931, Serial No. 523,603

2 Claims. (Cl. 78-60) This invention relates to the manufacture of cup shaped articles such as internal combustion engine pistons and the like, and particularly to an upsetting apparatus for making such articles.

One object of this invention is the provision of a simple and effective apparatus for upsetting metal to form-pistons and the like. Other objects are to provide a plunger member arranged to co-operate with a die to form pistons having wrist pin bosses interiorly thereof, and to provide means for forming a flange or other element overhanging the interior surface of the piston. Other objects will appear hereinafter.

In the accompanying drawings:

Fig. 1 is a view partly in section and partly in elevation of a part of the apparatus.

Fig. 2 is a similar view showing the plunger in position within the die.

Fig. 3 is a view similar to Fig. 1 of another part of the apparatus.

Fig. 4 is a similar view of the structure shown in Fig. 3 showing the plunger in position against the die.

Fig. 5 is an exploded view of the divided core shown in Figs. 3 and 4.

Referring to :the drawings, the numeral I0 designates generally a plunger arranged to co-operate with a divided die II to upset a slug or billet of metal l2 into the form of a piston. The plunger I0 is formed with a cylindrical portion l3 having oppositely disposed recesses I4 and I5 extending inwardly in uniform section from the end face l6 of the plunger and designed to form wrist pin bosses on the interior of the piston. The end face It of the plunger is preferably provided with one or more grooves l1 to form reinforcing ribs on the interior surface of the piston head and the cylindrical portion l3 terminates in an annular shoulder l8 designed to shape the end edge of the piston skirt.

The divided die ll consists of a pair of die halves l9 and 20 each provided with a semicylindrical recess 2| arranged to register and form a'cylindrical opening to receive and shape the outer surface of the piston. The die halves l9 and 20 are mounted for relative movement in any suitable type of die holders and are designed to be locked rigidly together during the upsetting operation'. Upon the completion of this operation the die halves may be separated to dis-- charge the upset article. Since the means for -mounting and lockingthe die halves forms no part of the-present invention, be described in detail.

The plunger Ill is connected to any suitable the same will not -the other wrist pin boss.

type of machine for forcing the same into the die H and upsetting the billet l2. It will be evident that this operation will cause the metal I2 to flow into the form of a piston 22 as illustrated in I Fig. 2. a 5 For the purpose of forming a flange on the open end of the skirt the piston 22, after completion of the initial upsetting operation, is placed in a divided die 23 which may be similar to the die I I previously described, as illustrated in Fig. 3. 1o

A sectional core; designated generally by the numeral 24, and shown in detail in Figs. 3, 4, and 5, is assembled within the piston. This core preferably consists of a central member 25, two side members 26 and 21, and four corner members 28, 29, 39 and 3| all of which flt together to provide an exterior surface conforming to the desired interior surface of the piston. The central member 25 is rectangular in section andis provided with a stem 32 terminating in an enlarged head 33, the under surface of which forms a shoulder 34. The side members 26 and'21 are of substantially the same width as two of the opposed sides of the central member 25 and are arranged to fit against such sides. The outer surface of each of the side members 26 and 21 is ar-' ranged to conform to a portion of the interior cylindrical surface of the piston. These outer surfaces of the side members are joined by inwardly extending shoulders 35-to concentric arcuate surfaces 36 which terminate in shoulders 31. Beyond the shoulders 31 the side members 26 and 21 are continued to form shanks 38 arranged to abut against the shoulder 34 to position the side members longitudinally with respect to the central member.

The corner members 28 and 29 fit together and against one plane side of the assembled members 25, 26, and 21, and the corner members 30 and 3| similarly fit against the opposite side, thereby, forming a complete cylindrical assembly. The abutting surfaces of the members 28 and 29 are formed with registering recesses 39 which together form a space to receive one of the wrist pin bosses of the piston. Similarly, the members 30 and 3| 'are formed with recesses 40 to receive Each of the members 28, 29, 30 and 3| is provided with a shoulder 35, arcuate surface 35, shoulder 31, and shank 33, corresponding to the side members 29 and 21, so that the assembled core presents an annular shoulder 35, a cylindrical surface 36 concentric with the outer surface of the core, and an annular shoulder 31.

A plunger 4| isarranged to co-operate with the die 23 and core 24 to upset the open end of the piston 22 into the recess formed by the annular shoulder 35 and the cylindrical surface 36. This plunger includes a projecting annulus 42 having an end face 43 and a central recess 44. The recess 44 is arranged to receive the assembled stem 32 and shanks 38 and is of such depth that the bottom surface 45 thereof engages the head 33 simultaneously with the engagement of the end face 43 of the annulus with the annular shoulder 31 of the core.

As shown in Fig. 4, the annulus 42 fits within the die 23 when forced inwardly by suitable means, and first engages the open end of the skirt of the piston 22. Continued movement of the plunger upsets the metal of the piston into the recess formed by the shoulder 35 and cylindrical surface 36. The annulus 45 then engages the shoulder 31, and simultaneously the bottom wall 45 of the recess engages the head 33, completing the shaping of the piston.

It will be evident that the foregoing operation forms an inwardly projecting flange 46 on the open end of the piston. The plunger ll is then withdrawn and the completed piston is freed from the core and die. To, accomplish this, the locking devices holding the die sections l9 and together may be first eased off 'so as to relieve a part of the pressure existing between the core and die. The central core member is then withdrawn longitudinally or axially of the piston. This operation may be facilitated by tapering the member 25 so that the initial withdrawing movement thereof relieves the remaining pressure between .:.;t.he core members. The side members 26 and 21 are then moved laterally radially of the piston into the central cleared space formed by the removal of the member 25 until the shoulders thereof clear the flange 46 and are then withdrawn longitudinally or axially of the piston.

longitudinally from the piston. The lateral movement of the side and corner members is facilitated by the arrangement of the surfaces thereof which contact with the piston walls, the divergent relation of such surfaces permitting freeing of .the core members upon the initial movement thereof. For this purpose the inner surfaces of ton is removed therefrom. It will be evident that with the core and plunger constructed as illustrated the flange II is formed on the extreme end ofthe piston and is circumferentially complete. It is to be understood, however, that the flange may, if desired, be divided or .made in any suitable length and maybe located any convenient distance from the extreme end of the skirt.

During separation of the piston from the core members and die sections any freezing or sticking due to cooling and contraction of the piston or due to the pressure applied by the plunger may be readily relieved with little or no danger of breaking or injuring the piston, since the worked metallic structure possesses a considerably higher tensile strength than a casting. This permits the 5 application of greater force to the core members to separate them from the piston and reduces the skill and care required in manufacturing in addition to reducing to a minimum the loss from broken or damaged articles. Furthermore, less 10 pressure is developed against the core by shrinkage of the pistons than is the case in casting, since the initial temperature of the metal is below the freezing or solidification point and the fall in temperature during the upsetting operations 15 may be maintained at a minimum.

The apparatus disclosed herein is intended primairly for use in carrying out the process disclosed in my co-pending application, Serial No. 523,602 filed March 18, 1931 and to produce the 20 piston disclosed and claimed in my co-pending application, Serial No. 525,277 filed March 25. 1931.

Although the foregoing description is neces-- sarily of a detailed character in order that the in- 2 vention may be fullydisclosed, it is to be understood that the specific terminology employed is not to be construed as restrictive or limiting, and it is to be further understood that various rear-- rangements of parts and modifications of detail may be resorted to without departing from the spirit and scope of the invention as defined in the following claims.

I claim:

1. Apparatus for upsetting or forging articles comprising, in combination, a confining die hav-. ing a substantially cylindrical recess open at one end and closed at the other, adapted to receive a cup shaped metal blank having an open end and a closed end, a multlpart core arranged to be placed within and to partially fit the blank and having an external surface conforming to the desired in temal surface of the completed article, and a re-. ciprocable ram having an annular working me arranged to enter the open end of said die and engage the edge of the open end of the blank to upset the metal of the blank against the outer surface of said core and into the cylindrical re-. cess of said die, said ram also having a face to' .engage said core after a predetermined movement. 59

- ram having an annular working face and a re- 'cess, said ram arranged to enter the end of said die to upset the metal of the blank against the outer surface of said core, said recess receiving the stem of said core to center same during the working of the blank.

ALFRED mom 

